The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 1993
Filed:
Jul. 26, 1990
Koichi Takeuchi, Amagasaki, JP;
Osamu Ito, Amagasaki, JP;
Kyosuke Yoshimoto, Amagasaki, JP;
Kunimaro Tanaka, Amagasaki, JP;
Isao Watanabe, Amagasaki, JP;
Kazuhiko Tsutsumi, Amagasaki, JP;
Ryuichirou Aria, Amagasaki, JP;
Yoshihiro Kiyose, Amagasaki, JP;
Kazuhiko Nakane, Amagasaki, JP;
Teruo Furukawa, Amagasaki, JP;
Masayoshi Shimamoto, Amagasaki, JP;
Yoshiyuki Nakaki, Amagasaki, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
Methods and apparatuses are disclosed for improving accuracy of recording and reproducing information onto and from a magneto-optic recording information medium. In the first method, a width of a mark formed by a relatively low intensity light beam between two kinds of light beam intensities used for recording information is made larger than a sum of a track land width and the maximum track offset of the light beam, thereby the mark formed by the relatively low intensity light beam covers the track land portion in its full width. In the first apparatus, a reflected light beam from the magneto-optic recording information medium is split into a reflected beam for information reproducing and a reflected beam for tracking and focusing servos at the reproducing, thereby the apparatus can remove part being affected by the track groove portion from the reflected light beam for information reproducing. In the second method and apparatus, an intensity ratio of the two kinds of intensities of light beams used for information recording is controlled in such a manner that a mark width formed by the relative low intensity light beam is wider than a mark width formed by the relative high intensity light beam.